The present invention relates to an intermediate connection electrical connector for connecting a mating connector or a circuit board as a relative connecting member. In particular, the present invention relates to an intermediate connection electrical connector suitable for transmitting a signal at a high speed (a high frequency).
A conventional intermediate connection electrical connector includes a plurality of blades, in which a plurality of terminals is arranged as a terminal group in a high density on a surface of a flat substrate formed of an electrical insulating member. The blades are arranged at a certain interval in a thickness direction thereof. Further, the conventional intermediate connection electrical connector includes a housing for holding the blades. In each blade, contact sections of the terminal group are positioned on a side of one end and a side of the other end thereof, so as to be capable of connecting to respective mating connecting members.
For example, Patent Reference discloses a conventional intermediate connection electrical connector for connecting a mating connector (a backplane connector) and a circuit board (a daughter card). The conventional intermediate connection electrical connector has a plurality of blades, which are referred to as “wafers” having rectangular flat shapes. On each blade, contact sections on a side of one end (a side to be connected to the mating connector) of the terminal group are arranged on one side thereof, and the contact sections on a side of the other end of the terminal group (the side to be connected to the circuit board) are arranged on another side thereof that is perpendicular to the one side. The blades are used as pair terminals whereby two adjacent terminals transmit differential signals.    Patent Reference: Japanese Patent Publication of Translated Version No. 2008-545250
In the conventional intermediate connection electrical connector disclosed in Patent Reference, in each blade, between the contact sections of the pair terminals, i.e., between the two adjacent contact sections and the next adjacent contact sections, there is formed a cavity, and a lossy insert is attached thereto. The lossy insert disclosed in the Patent Reference is made of an electrically lossy material (an electromagnetic wave-absorbing material). Such an electrically lossy material is a conductor as a whole, but is a relatively poor conductor relative to a specific frequency. Therefore, the lossy insert absorbs unnecessary electromagnetic waves (a noise) coming from each other, so that the terminals located on both sides of the lossy insert are shielded from the noise, thereby preventing so-called “crosstalk” between the terminals. Such an electrically lossy material may be obtained, for example, by adding filler containing conductive particles to a binder.
According to Patent Reference, the lossy insert is provided between the contact sections of the pair terminals and the contact sections of the adjacent pair terminals. Accordingly, it is possible to prevent the crosstalk at the contact sections between the pair terminals of the blade.
According to Patent Reference, the mating connector accommodates a portion of each blade on a side of one end (a part on which one ends of the terminal group is located) while being in a state that a plurality of blades is arranged in the blade thickness direction. Further, the mating connector is connected to the connecting sections on a side of one ends of the terminals group of the blade. In addition, the mating connector has a grounding plate (a shielding plate) having a flat surface thereof perpendicular to the plate thickness direction, and is configured to be connected to the lossy insert of the blade.
As described above, according to Patent Reference, the lossy insert for preventing the crosstalk is attached to the blade. Accordingly, it is possible to prevent the crosstalk between the contact sections of the two adjacent pair terminals within the blade.
However, in the conventional intermediate connection electrical connector, the lossy insert is not provided between the blades, and further the lossy insert is not provided at a position on the mating connector corresponding to a position between the blades. In other words, before and after connecting the conventional intermediate connection electrical connector and the mating connector, there is no lossy insert present between the blades.
In addition, the mating connector has the grounding plate at a position corresponding to a position between the blades. Accordingly, in a state that the conventional intermediate connection electrical connector is connected to the mating connector, the unnecessary electromagnetic waves irradiated from the terminals of each blade tend to be transferred onto the grounding plate. As a result, resonance sometimes occurs between the grounding plates that are adjacent to each other, and the resonance could be picked up as the noise by the terminal of another blade adjacent thereto.
In order to solve the problems of the conventional intermediate connection electrical connector described above, an object of the present invention is to provide an intermediate connection electrical connector capable of significantly reducing the resonance between grounding sections.
Further objects and advantages of the present invention will be apparent from the following description of the present invention.